Operation of SMES for the Current Source Inverter Fed Distributed Power System Under Islanding Mode

The purpose of this paper is to propose the collaborative operation schemes of superconducting magnetic energy storage (SMES) for the current source inverter fed distributed power system (DPS) under the islanding mode. The key is to propose the closed-loop output voltage control for the current source inverter fed SMES to support the bus voltage at point of common coupling when the DPS is disconnected from the main grid. The droop control of voltage amplitude and frequency is designed to make different SMES units share the loads in DPS equally. To mitigate the effect of uncertain line impedance on power sharing, the virtual impedance control is added to construct a virtual output inductance for the SMES. The grid-connected operation is also proposed for the SMES to provide stable output power when the DPS is connected to the main grid. The computer simulation is carried out to verify the performance of the proposed operation schemes.